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Cheap flights from Seattle to Washington, D.C. Dulles Intl Airport from C$ 244

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 25/8. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — IAD
24 Aug — 31 Aug1
1 adult
1 adult, Economy, 0 bags
Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl are usually found in February or October, booked 75 days in advance, depart on a Thursday or Tuesday and return on a Monday

Cheap flight deals from Seattle to Dulles Intl

Enter your travel dates to find the best prices.

Cheapest flights from Seattle to Dulles Intl
Explore the most affordable flight options available from Seattle to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 25 July 2026.

Thu 3/91:57 p.m.
SEA
-
IAD
1 stop7h 47m
United Airlines
Sun 13/95:33 p.m.
IAD
-
SEA
Nonstop5h 45m
United Airlines
Deal found 21/7C$ 407
Tue 1/911:00 p.m.
SEA
-
IAD
1 stop7h 28m
United Airlines
Sun 6/91:20 p.m.
IAD
-
SEA
Nonstop5h 46m
United Airlines
Deal found 20/7C$ 414
Tue 25/83:56 p.m.
SEA
-
IAD
Nonstop5h 03m
Alaska Airlines
Tue 1/99:03 a.m.
IAD
-
SEA
Nonstop5h 36m
Alaska Airlines
Deal found 22/7C$ 416
Wed 2/98:38 a.m.
SEA
-
IAD
Nonstop5h 06m
Alaska Airlines
Mon 7/97:00 a.m.
IAD
-
SEA
Nonstop5h 37m
Alaska Airlines
Deal found 21/7C$ 417
Thu 3/99:35 p.m.
SEA
-
IAD
Nonstop5h 05m
Alaska Airlines
Mon 7/97:00 a.m.
IAD
-
SEA
Nonstop5h 37m
Alaska Airlines
Deal found 23/7C$ 420
Thu 3/910:55 a.m.
SEA
-
IAD
1 stop8h 24m
United Airlines
Mon 7/91:20 p.m.
IAD
-
SEA
Nonstop5h 46m
United Airlines
Deal found 22/7C$ 421
Thu 10/93:56 p.m.
SEA
-
IAD
Nonstop5h 03m
Alaska Airlines
Sun 13/97:47 p.m.
IAD
-
SEA
1 stop16h 33m
Alaska Airlines
Deal found 25/7C$ 423
Sat 29/811:59 p.m.
SEA
-
IAD
1 stop8h 29m
United Airlines
Tue 1/91:20 p.m.
IAD
-
SEA
Nonstop5h 46m
United Airlines
Deal found 21/7C$ 425
Wed 26/83:58 p.m.
SEA
-
IAD
Nonstop5h 01m
Delta
Fri 28/87:10 a.m.
IAD
-
SEA
Nonstop5h 45m
Delta
Deal found 22/7C$ 428
Thu 3/93:56 p.m.
SEA
-
IAD
Nonstop5h 03m
Alaska Airlines
Sat 5/95:47 p.m.
IAD
-
SEA
Nonstop5h 47m
Alaska Airlines
Deal found 22/7C$ 430
Fri 25/93:56 p.m.
SEA
-
IAD
Nonstop5h 03m
Alaska Airlines
Sun 4/107:02 a.m.
IAD
-
SEA
Nonstop5h 42m
Alaska Airlines
Deal found 22/7C$ 431

Find flight deals from Seattle to Dulles Intl

Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) to Dulles Intl (IAD). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated 25 July 2026.

Round-trip from

C$ 407

One-way from

C$ 244

Popular in

January

Cheapest in

February

Average price

C$ 687

Good round-trip deal

C$ 1,966 or less
United Airlines
  • United Airlines
  • 3/9-13/9
  • 1 total stop
  • 13h 32m total
  • Seattle to Washington, D.C.
Search Deals
Alaska Airlines
  • Alaska Airlines
  • 25/8
  • 1 total stop
  • 18h 25m total
  • Seattle to Washington, D.C.
Search Deals
Highest demand for flights based on searches. 9% potential increase in price (C$ 88 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 5% potential price decrease (C$ 43 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in July 2026
Search Deals
Price to beat on a round-trip flight from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl.
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Seattle to Dulles Intl that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 629,999 searches. Data last updated 25 July 2026.
Use the filters below to find and compare flights from Seattle to Washington, D.C. Dulles Intl Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 23/9

9:35 p.m.-5:40 a.m.

Nonstop5h 05m

Washington, D.C. Dulles Intl

Sun 11/10

9:38 a.m.-12:20 p.m.

Nonstop5h 42m

C$ 438
Quickest round-trip

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Tue 25/8

9:35 p.m.-5:40 a.m.

Nonstop5h 05m

Washington, D.C. Dulles Intl

Thu 27/8

7:00 a.m.-9:37 a.m.

Nonstop5h 37m

C$ 472

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Tue 25/8

9:35 p.m.-5:40 a.m.

Nonstop5h 05m

Washington, D.C. Dulles Intl

Fri 28/8

7:00 a.m.-9:37 a.m.

Nonstop5h 37m

C$ 472

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 19/8

9:35 p.m.-5:40 a.m.

Nonstop5h 05m

Washington, D.C. Dulles Intl

Wed 26/8

5:47 p.m.-8:34 p.m.

Nonstop5h 47m

C$ 479

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Thu 10/9

8:49 p.m.-6:14 p.m.

1 stop18h 25m

Washington, D.C. Dulles Intl

Mon 14/9

7:47 p.m.-9:20 a.m.

1 stop16h 33m

C$ 500

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Tue 6/10

3:56 p.m.-11:59 p.m.

Nonstop5h 03m

Washington, D.C. Dulles Intl

Tue 13/10

7:24 p.m.-9:28 a.m.

1 stop17h 04m

C$ 517

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 7/10

3:56 p.m.-11:59 p.m.

Nonstop5h 03m

Washington, D.C. Dulles Intl

Mon 12/10

7:24 p.m.-9:28 a.m.

1 stop17h 04m

C$ 545

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Sun 18/10

11:14 p.m.-7:17 a.m.

Nonstop5h 03m

Washington, D.C. Dulles Intl

Wed 21/10

5:45 p.m.-8:37 p.m.

Nonstop5h 52m

C$ 559

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Thu 13/8

4:01 p.m.-11:59 p.m.

Nonstop4h 58m

Washington, D.C. Dulles Intl

Tue 18/8

6:03 a.m.-8:48 a.m.

Nonstop5h 45m

C$ 627

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 12/8

11:59 p.m.-10:48 a.m.

1 stop7h 49m

Washington, D.C. Dulles Intl

Tue 18/8

7:10 a.m.-9:55 a.m.

Nonstop5h 45m

C$ 628

Flights are sorted by cheapest round-trip flights first.

Deals found on 20/7

Showing 1-10 of 22 resultsSorted by cheapest first
1
2
3

Best time to book a flight from Seattle to Dulles Intl

Have a flexible travel schedule? Discover the best time to fly to Dulles Intl from Seattle with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Seattle to Washington, D.C. Dulles Intl Airport

How far ahead should I book a flight from Seattle to Washington, D.C. Dulles Intl Airport?

Booking 74 days in advance of your planned departure date is, on average, the best time to get cheap flights from Seattle to Washington, D.C. Dulles Intl Airport. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

What is the cheapest month to book a flight from Seattle to Washington, D.C. Dulles Intl Airport?

Currently, February is the cheapest month in which you can book a flight from Seattle to Washington, D.C. Dulles Intl Airport (average of C$ 435). Flying from Seattle to Washington, D.C. Dulles Intl Airport in January is currently the most expensive (average of C$ 939). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from SEA to IAD?

Find hourly flight availability from Seattle to Dulles Intl. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 25 July 2026.

A simple way to save on the total cost of your ticket is to fly from Seattle to Washington, D.C. Dulles Intl Airport in the evening. If you’re flexible enough to do this you can expect to save up to 69% on your trip compared to booking a flight at noon.

How much does it cost to fly round-trip from Seattle to Washington, D.C. Dulles Intl Airport?

Airfare is below average for this route at the moment.

Seattle to Washington, D.C. Dulles Intl Airport flights typically cost between C$ 504 and C$ 771 in September.
The cheapest round-trip price found within the last 5 days was C$ 407 on United Airlines (3 Sep-13 Sep).

Reviews of airlines servicing Dulles Intl

Get insights into the airlines that provide service to Dulles Intl. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Dulles Intl. Reviews last updated 25 July 2026.
Read reviews from past customers who have flown Hawaiian Airlines from Seattle to Washington, D.C. Dulles Intl Airport. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Hawaiian Airlines
7.8
Good
2,821 reviews
Check prices

Entertainment

7.1

Comfort

7.7

Crew

8.5

Overall

7.8

Food

6.9

Boarding

8.0

Reviews

1 / 20
6.0
Good

Patrick,Feb 2026

SEA - PHX

Was not able to check in online, had to go to multiple lines at airport to get boarding pass and was not able to get a seat without going to the gate, wound up in middle in the back.
Hawaiian Airlines
7.8
Good
2,821 reviews
Hawaiian Airlines
7.8
Good
2,821 reviews
Check prices

Entertainment

7.1

Comfort

7.7

Crew

8.5

Overall

7.8

Food

6.9

Boarding

8.0

Reviews

1 / 20
6.0
Good

Patrick,Feb 2026

SEA - PHX

Was not able to check in online, had to go to multiple lines at airport to get boarding pass and was not able to get a seat without going to the gate, wound up in middle in the back.

Related info for your journey

Find useful and relevant information for your journey from Seattle to Dulles Intl. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly from for flights from Seattle to Washington, D.C. Dulles Intl?

    If you book a flight to Washington, D.C. Dulles Intl from Seattle, you will be flying from Seattle/Tacoma Intl, which is the city’s only airport. Seattle/Tacoma Intl (SEA) is located 18.4 km from the centre of Seattle. There are 20 flights from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl per day from 1 airline.

  • How long is the flight from Seattle to Washington, D.C. Dulles Intl Airport?

    Alaska Airlines can get you from Seattle to Washington, D.C. Dulles Intl Airport in just under 5h 05m. Your travel time will be generally consistent. Seattle and Washington, D.C. Dulles Intl Airport are separated by a distance of 3700 km. All flights are typically direct.

  • What is the cheapest airline to fly from Seattle to Washington, D.C. Dulles Intl Airport round-trip?

    Our cheapest airline available from Seattle to Washington, D.C. Dulles Intl Airport is Hawaiian Airlines. Our recent data shows that you can find tickets from as low as C$ 369 on this airline. Hawaiian Airlines is 40% cheaper than the average price of flights available within the next 90 days to this destination.

  • What are the most reliable airlines from Seattle to Washington, D.C. Dulles Intl Airport?

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Seattle to Washington, D.C. Dulles Intl Airport on time: Iberia (100%), Austrian Airlines (93%), Avianca (93%).

  • What are the cheapest flights from Seattle to Washington, D.C. Dulles Intl Airport?

    While on average a flight from Seattle to Washington, D.C. Dulles Intl Airport is generally C$ 2,077, our data shows the cheapest flight currently is C$ 1,966. When looking at the most popular route, (Seattle/Tacoma Intl - Washington, D.C. Dulles Intl), you can expect to pay C$ 418 for that flight.

  • Can I find deals for flights from Seattle to Dulles Intl that include hotel bookings?

    Yes. In addition to deals on Seattle to Dulles Intl flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Seattle to Dulles Intl?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to Dulles Intl.

  • Can I find deals for business class flights from Seattle to Dulles Intl?

    Yes. Cheapflights offers flight deals from Seattle to Dulles Intl by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Seattle to Washington, D.C. Dulles Intl Airport?

    Currently, February is the cheapest month in which you can book a flight from Seattle to Washington, D.C. Dulles Intl Airport (average of C$ 435). Flying from Seattle to Washington, D.C. Dulles Intl Airport in January is currently the most expensive (average of C$ 939). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Travelling to a place near Washington, D.C. Dulles Intl Airport?

Book flights to Washington, D.C. Dulles Intl Airport if you plan to visit one of these locations
Silver Spring
Warrenton
Winchester
Hanover
Oxon Hill
Gaithersburg
Reston
Chantilly
Herndon
Ellicott City
Arlington
Fredericksburg
Alexandria
Rockville

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Alternative routes for Seattle to Dulles Intl

See prices for flight routes from nearby airports that may be better suited for you.
Seattle to Reagan-National flights

Top airline flying from Seattle to Dulles Intl

Discover the top airline that operate flights from Seattle to Dulles Intl. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 629,999 searches. Data last updated 25 July 2026.
AirlineCheapestAverageFlexibilityOn-time
Hawaiian AirlinesCheapestC$ 369AverageC$ 369FlexibilityNo cancel feeOn-time85%
Search Hawaiian Airlines flights

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How does Cheapflights help users find flights from Seattle to Dulles Intl?

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Why should you use Cheapflights to find cheap flight tickets from Seattle to Dulles Intl?

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Can Cheapflights find flights from Seattle to Dulles Intl with no change fees?

Cheapflights does show flights with no change fees to all users. To see these options for flights from Seattle to Dulles Intl, users can toggle the no change fees filter when performing a flight search.

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